Philippa Kaur

More stories

  • 125 Shares189 Views

    in Humans

    Ancient footprints show children splashed in puddles 11,500 years ago

    A set of ancient footprints seems to show children splashing around in water that had pooled in tracks left by a now-extinct ground sloth

    Humans

    6 April 2022

    By Colin Barras
    A 3D model of footprints discovered at White Sands National Park, New Mexico, created from multiple photographs. It shows the prints of several prehistoric children jostling around the larger marks left by a giant ground slothDavid Bustos/Matthew Bennett
    The delight that children find when they jump in muddy puddles has a surprisingly long history. Fossil footprints discovered at an archaeological site in New Mexico show that a group of youngsters living at least 11,500 years ago spent a few carefree minutes engaged in some joyful splashing. But the world was very different back then: the puddles in question had formed in the deep footprints left by a now-extinct giant ground sloth.
    The footprints were discovered at White Sands National Park, a site that is rapidly gaining a reputation for its astonishing archaeology. Within the park, there is a playa – a dried up lake-bed – some 100 square kilometres in size. The playa contains thousands of footprints left by humans, mammoths, sabre-toothed cats and other inhabitants of prehistoric North America. Some of the tracks suggest that humans had reached the Americas 23,000 years ago – about 8000 years earlier than we had thought.
    But what really sets the ancient human footprints at White Sands apart is their power to vividly show us what life was like for early Americans. Matthew Bennett at Bournemouth University, UK, has been studying tracks at the site for several years. He and his team can measure the prints to work out things like the age of the person who made them and how fast they were walking or running. Then, they can follow them and see how events such as animal hunts unfolded. “It’s written in the tracks what happened,” says Bennett.Advertisement
    In unpublished work, Bennett and his team have found one collection of prints that tell a particularly evocative tale. It begins with a set of roughly 40-centimetre-long footprints that show a giant ground sloth – measuring perhaps 3 metres from nose to tail – once lumbered across the landscape.
    Later, a group of three to five small children showed up. The jumbled mess of footprints they left are focused around one sloth print. The way the children’s tracks deform the sloth print tells us that the ground was wet, says Bennett. It is impossible to be certain about what was going on, but Bennett says the best interpretation is that water had pooled in the sloth print to create a puddle that was perfect for splashing in – an irresistible target for children, even in prehistory.

    Kevin Hatala at Chatham University in Pennsylvania says he is excited to learn more about the tracks once they appear in a formal scientific report. “Records like this demonstrate the unique potential for footprints to record information that is extremely difficult, if not impossible, to observe or infer from other materials such as bones and stone tools,” he says.
    Kim Charlie and her sister, Bonnie Leno, have made trips to see Bennett and his colleagues at work, studying the prints. They are both members of the Pueblo of Acoma near Albuquerque in New Mexico, one of several groups of Pueblo people who feel a spiritual connection to White Sands.
    Charlie is fascinated by the idea that giant ground sloths were so common in the world inhabited by the first humans at White Sands, who may be among the ancestors of the present-day Pueblo people. “It’s fascinating,” says Charlie. “And you think: jeez, were these animals friendly?”
    Sign up to Our Human Story, a free monthly newsletter on the revolution in archaeology and human evolution

    More on these topics: More

  • 163 Shares99 Views

    in Humans

    How fossil footprints are revealing the joy and fear of Stone Age life

    A new wave of archaeological investigations is reconstructing intimate details of our ancestors’ lives from fossilised footprints. They give us glimpses of everything from parent-child relationships to the thrill of a giant sloth hunt

    Humans

    6 April 2022

    By Colin Barras
    Rupert Gruber
    A YOUNG woman is struggling across a muddy plain with a 3-year-old child on her left hip. She puts the youngster down to catch her breath. But she is too afraid to pause for long. The pair are alone, an easy target for the sabre-toothed cats that may lurk nearby. She picks up the child again and hurries on, vanishing into the distance. For a time, all is quiet. Then a giant ground sloth plods across the path she took. The animal catches the woman’s scent and is instantly on guard, rearing up and turning to scan the landscape for human hunters.
    What was it like to live in the Stone Age? There must have been moments of joy, fear, love, pain and perhaps even wonder for the people who inhabited Earth tens of thousands of years ago. But emotions don’t fossilise, so we are shut out of those moments, separated by a vast chasm of time. We can find all the bones and tools we like, but they won’t tell us about the experience of life for our ancient ancestors.
    Then again, a new window on their everyday existence may be cracking open. As people went about their lives, they left untold numbers of footprints behind. These recorded their behaviour in a unique way, capturing everything from nervous shuffles to determined sprints. What’s more, the tracks have an order to them, meaning events can be read like a narrative. That story of the woman, the child and the giant sloth is a vivid example we have found written in ancient tracks – but it certainly isn’t the only … More

  • 138 Shares149 Views

    in Space & Astronomy

    A star nicknamed ‘Earendel’ may be the most distant yet seen

    A chance alignment may have revealed a star from the universe’s first billion years.

    If confirmed, this star would be the most distant one ever seen, obliterating the previous record (SN: 7/11/17). Light from the star traveled for about 12.9 billion years on its journey toward Earth, about 4 billion years longer than the former record holder, researchers report in the March 30 Nature. Studying the object could help researchers learn more about the universe’s composition during that early, mysterious time.

    “These are the sorts of things that you only hope you could discover,” says astronomer Katherine Whitaker of the University of Massachusetts Amherst, who was not part of the new study.

    Sign Up For the Latest from Science News

    Headlines and summaries of the latest Science News articles, delivered to your inbox

    Thank you for signing up!

    There was a problem signing you up.

    The researchers found the object while analyzing Hubble Space Telescope images of dozens of clusters of galaxies nearer to Earth. These clusters are so massive that they bend and focus the light from more distant background objects, what’s known as gravitational lensing (SN: 10/6/15).

    In images of one cluster, astronomer Brian Welch of Johns Hopkins University and colleagues noticed a long, thin, red arc. The team realized that the arc was a background galaxy whose light the cluster had warped and amplified.

    Atop that red arc is a bright spot that is too small to be a small galaxy or a star cluster, the researchers say. “We stumbled into finding that this was a lensed star,” Welch says.

    The researchers estimate that the star’s light originates from only 900 million years after the Big Bang, which took place about 13.8 billion years ago.

    Welch and his colleagues think that the object, which they poetically nicknamed “Earendel” from the old English word meaning “morning star” or “rising light,” is a behemoth with at least 50 times the mass of the sun. But the researchers can’t pin down that value, or learn more about the star or even confirm that it is a star, without more detailed observations.

    The researchers plan to use the recently launched James Webb Space Telescope to examine Earendel (SN: 10/6/21). The telescope, also known as JWST, will begin studying the distant universe this summer.

    JWST may uncover objects from even earlier times in the universe’s history than what Hubble can see because the new telescope will be sensitive to light from more distant objects. Welch hopes that the telescope will find many more of these gravitationally lensed stars. “I’m hoping that this record won’t last very long.” More

  • 88 Shares169 Views

    in Space & Astronomy

    Binary stars keep masquerading as black holes

    As astronomy datasets grow larger, scientists are scouring them for black holes, hoping to better understand the exotic objects. But the drive to find more black holes is leading some astronomers astray.

    “You say black holes are like a needle in a haystack, but suddenly we have way more haystacks than we did before,” says astrophysicist Kareem El-Badry of the Harvard-Smithsonian Center for Astrophysics in Cambridge, Mass. “You have better chances of finding them, but you also have more opportunities to find things that look like them.”

    Two more claimed black holes have turned out to be the latter: weird things that look like them. They both are actually double-star systems at never-before-seen stages in their evolutions, El-Badry and his colleagues report March 24 in Monthly Notices of the Royal Astronomical Society. The key to understanding the systems is figuring out how to interpret light coming from them, the researchers say.  

    Sign Up For the Latest from Science News

    Headlines and summaries of the latest Science News articles, delivered to your inbox

    Thank you for signing up!

    There was a problem signing you up.

    In early 2021, astronomer Tharindu Jayasinghe of Ohio State University and his colleagues reported finding a star system — affectionately named the Unicorn — about 1,500 light-years from Earth that they thought held a giant red star in its senior years orbiting an invisible black hole. Some of the same researchers, including Jayasinghe, later reported a second similar system, dubbed the Giraffe, found about 12,000 light-years away.

    But other researchers, including El-Badry, weren’t convinced that the systems harbored black holes. So Jayasinghe, El-Badry and others combined forces to reanalyze the data.

    To verify each star system’s nature, the researchers turned to stellar spectra, the rainbows that are produced when starlight is split up into its component wavelengths. Any star’s spectrum will have lines where atoms in the stellar atmosphere have absorbed particular wavelengths of light. A slow-spinning star has very sharp lines, but a fast-spinning one has blurred and smeared lines.

    “If the star spins fast enough, basically all the spectral features become almost invisible,” El-Badry says. “Normally, you detect a second star in a spectrum by looking for another set of lines,” he adds. “And that’s harder to do if a star is rapidly rotating.”

    That’s why Jayasinghe and colleagues misunderstood each of these systems initially, the team found.

    “The problem was that there was not just one star, but a second one that was basically hiding,” says astrophysicist Julia Bodensteiner of the European Southern Observatory in Garching, Germany, who was not involved in the new study. That second star in each system spins very fast, which makes them difficult to see in the spectra.

    What’s more, the lines in the spectrum of a star orbiting something will shift back and forth, El-Badry says. If one assumes the spectrum shows just one average, slow-spinning star in an orbit — which is what appeared to be happening in these systems at first glance — that assumption then leads to the erroneous conclusion that the star is orbiting an invisible black hole.

    Instead, the Unicorn and Giraffe each hold two stars, caught in a never-before-seen stage of stellar evolution, the researchers found after reanalyzing the data. Both systems contain an older red giant star with a puffy atmosphere and a “subgiant,” a star on its way to that late-life stage. The subgiants are near enough to their companion red giants that they are gravitationally stealing material from them. As these subgiants accumulate more mass, they spin faster, El-Badry says, which is what made them undetectable initially.

    “Everyone was looking for really interesting black holes, but what they found is really interesting binaries,” Bodensteiner says.

    These are not the only systems to trick astronomers recently. What was thought to be the nearest black hole to Earth also turned out to be pair of stars in a rarely seen stage of evolution (SN: 3/11/22).

    “Of course, it’s disappointing that what we thought were black holes were actually not, but it’s part of the process,” Jayasinghe says. He and his colleagues are still looking for black holes, he says, but with a greater awareness of how pairs of interacting stars might trick them. More

  • 150 Shares149 Views

    in Space & Astronomy

    When the Magellanic Clouds cozy up to each other, stars are born

    Like two great songwriters working side by side and inspiring each other to create their best work, the Magellanic Clouds spawn new stars every time the two galaxies meet.

    Visible to the naked eye but best seen from the Southern Hemisphere, the Large and Small Magellanic Clouds are by far the most luminous of the many galaxies orbiting the Milky Way. New observations reveal that on multiple occasions the two bright galaxies have minted a rash of stars simultaneously, researchers report March 25 in Monthly Notices of the Royal Astronomical Society: Letters.

    Astronomer Pol Massana at the University of Surrey in England and his colleagues examined the Small Magellanic Cloud. Five peaks in the galaxy’s star formation rate — at 3 billion, 2 billion, 1.1 billion and 450 million years ago and at present — match similarly timed peaks in the Large Magellanic Cloud. That’s a sign that one galaxy triggers star formation in the other whenever the two dance close together.

    Sign Up For the Latest from Science News

    Headlines and summaries of the latest Science News articles, delivered to your inbox

    Thank you for signing up!

    There was a problem signing you up.

    “This is the most detailed star formation history that we’ve ever had of the [Magellanic] Clouds,” says Paul Zivick, an astronomer at Texas A&M University in College Station who was not involved in the new work. “It’s painting a very compelling picture that these two have had a very intense set of interactions over the last two to three gigayears.”

    Even as the two galaxies orbit the Milky Way at 160,000 and 200,000 light-years from Earth, they also orbit each other (SN: 1/9/20). Their orbit is elliptical, which means they periodically pass near each other. Just as tides from the moon’s gravity stir the seas, tides from one galaxy’s gravity slosh around the other’s gas, inducing star birth, says study coauthor Gurtina Besla, an astrophysicist at the University of Arizona in Tucson.

    During the last encounter, which happened 100 million to 200 million years ago, the smaller galaxy probably smashed right through the larger, Besla says, which sparked the current outbreak of star birth. The last star formation peak in the Large Magellanic Cloud occurred only in its northern section, so she says that’s probably where the collision took place.

    Based on the star formation peaks, the period between Magellanic encounters has decreased from a billion to half a billion years. Besla attributes this to a process known as dynamical friction. As the Small Magellanic Cloud orbits its mate, it passes through the larger galaxy’s dark halo, attracting a wake of dark matter behind itself. The gravitational pull of this dark matter wake slows the smaller galaxy, shrinking its orbit and reducing how much time it takes to revolve around the Large Magellanic Cloud.

    The future for the two galaxies may not be so starry, however. They recently came the closest they’ve ever been to the Milky Way, and its tides, Besla says, have probably yanked the pair apart. If so, the Magellanic Clouds, now separated by 75,000 light-years, may never approach each other again, putting an end to their most productive episodes of star making, just as musicians sometimes flounder after leaving bandmates to embark on solo careers. More

  • 163 Shares99 Views

    in Humans

    Fate of buried Java Man revealed in unseen notes from Homo erectus dig

    One of the first excavations to find extinct human remains took place on Java in the 1890s, and the original documentation reveals details about the mudflow that encased the fossils there

    Humans

    30 March 2022

    By Michael Marshall
    Archaeological dig in Indonesia where the Java Man fossils were foundpublic domain sourced / access rights from Paul Fearn / Alamy Stock Photo
    The first large excavation of ancient human remains in Indonesia, in the 1890s, were done with great care – according to an analysis of unpublished documents from the dig.
    The original excavations revealed that Homo erectus on Java lived in a lush valley alongside a range of large animals, including antelope and elephants. Researchers including Paul C. H. Albers at the Naturalis Biodiversity Center in the Netherlands have analysed the records, and they say the animals in the fossil bed … More

  • 163 Shares99 Views

    in Humans

    Europe must tackle its energy crisis now or face a very painful winter

    Martin Meissner/AP/Shutterstock
    “THE time to repair the roof is when the sun is shining,” US president John F. Kennedy once said. It is an adage that Europe must now wrestle with.
    With spring blossoming even as war continues to darken the continent, it is hard to spend too much time thinking about next winter. Yet the geopolitical uncertainty created by Russia’s invasion of Ukraine means volatile energy prices are guaranteed this year. UK energy bill projections for October have yo-yoed with oil and gas prices in recent weeks, from a high of £3000 a year on average to a still-very-high low of … More

  • 113 Shares149 Views

    in Humans

    Michael Owen eyes up a new career in cryptocurrency

    Feedback is our weekly column of bizarre stories, implausible advertising claims, confusing instructions and more

    Humans

    30 March 2022

    Josie Ford
    On Earth …
    As a fresh-faced 18-year-old, Michael Owen’s mazy run from the centre circle to score against Argentina in the 1998 World Cup round of 16 raised hopes of a new golden era of English football – “soccer”, we add, looking in no particular direction – just as surely as David Beckham’s subsequent sending-off and the inevitable loss on penalties dashed them. Back then, it was only 32 years of hurt; by now it is getting silly.
    Altogether more forward-facing is Owen’s recent reinvention as a crypto guru. “Looks to me like blockchain is here to stay,” he announced last month on Twitter, hence he was working with a blockchain specialist on “a really exciting new football project”.
    Rapid reaction on the social media site renowned for rapid unkind reaction was predictably unkind, largely along the lines that Owen possibly didn’t actually know what blockchain is. If so, he is welcome to join our club any time.Advertisement
    This seems to follow a trend of ex-elite sportspeople advertising cryptocurrency projects, something we can associate with the ennui and need for new revenue streams associated with being an ex-elite sportsperson. We click further, on our eternal quest for both excitement and enlightenment. “The first Michael Owen official NFT collection comprises of 1233 NFT’s that are available across 5 increasingly exclusive tiers,” we read. We are somewhat the wiser: the blockchain is about football stickers. Welcome to the future.
    … as it is in heaven
    And much, much good may come of this sort of thing, going by a press release on behalf of a “visionary NFT production house” thrust our way by a colleague with eyes not so much rolling as whirling like pulsars.
    collection – although the words quoted are from a press release so don’t appear there. Richard says he didn’t include it as it’s a money-making operation; up to you if you still want to put in, I think it’s fine without “On April 3, they’re launching 30 NFTs from their bestselling ‘Greatest Minds of Our Time’ – pop-art images of inspirational figures, such as Oprah, Elon Musk, and the Dalai Lama – into orbit on SpaceX,” the PR puff breathlessly informs us. “Once in space, passenger Israeli air force pilot Eytan Stibb [sic] will call them up on his tablet and bless them with starlight and cosmic rays. He’ll then ‘drop’ them from space directly into the blockchain collection.”
    The selection of great minds of our time is interesting, but the ultimate aim – to auction the widgets off for the benefit of clean-water charities – is laudable. The whole process does strike us as a mite overcomplicated, though, given that starlight and cosmic rays are freely available on Earth. An interesting metaphysical question is, if digital art exists only when constituted as pixels, and is called into life only when in orbit, has it been launched into orbit?
    No matter. We detect a whiff of good old performance art in all this, so we will politely just nod and smile.
    Small island far away
    Ceri Brown writes from Haverfordwest in Wales, querying a Sky News story about the position of Henderson Island, part of the Pitcairn group in the South Pacific that through historical accident finds itself a UK Overseas Territory. Populated largely by native crabs and non-native plastic waste, it is perhaps a measure of the seriousness with which the UK has taken its stewardship up till now that the Royal Navy recently found it situated about 1.5 kilometres to the south of where it thought it was.
    “Henderson Island is uninhabited and is about the size of Oxford,” the article states, presumably following the principle of British units for British places. “Could you convert that to fractions of a Berkshire please?” asks Ceri, catching us slightly off guard. No, but in standard Imperial units, it is a smidgen under 2 milliWales. That is if anyone is actually sure how big Henderson Island is.
    Atmospheric surge
    This admirable effort to make global news local sends us rootling in our piles for a headline from the Essex Live website in the UK sent in by Anthony Jamieson in January. “Essex sees huge atmospheric pressure surge as Hunga Tonga volcanic eruption felt across East Anglia”, it screams, adding in smaller typeface that the pressure in Heybridge, Essex, jumped “from just over 1,023 millibars of pressure to 1,024”. No eardrums burst, we hope.
    Out of time
    Gerben Wierda writes from the Netherlands currying favour – quite our favourite curryable material – and challenging the orthodoxy that true New Scientist aficionados read the magazine back to front.
    “I read NS from front to back,” he says, “but Feedback plays an important role in my NS backlog management. If I come across an issue and I am uncertain if it has been read, I check the first entry in Feedback.” We are thus not only the most memorable bit of the magazine, he says, but “like dessert: that most enjoyable end of a good experience.”
    Your cheque is in the post. Of course, we recognise that the true measure of an aficionado of this magazine is a backlog of issues that you always convince yourself you are going to clear. Being stuck on the issue of 9 October 2021 has its advantages, says Gerben. “One can read news articles about the possible rise of the new delta variant of covid-19 and remain in a world that is still blissfully free of war crimes being performed in Ukraine.” We hear you.
    Got a story for Feedback?
    You can send stories to Feedback by email at [email protected]. Please include your home address. This week’s and past Feedbacks can be seen on our website. More